1650s, "a ghost, specter," from Latin larva (plural larvae), earlier larua "ghost," also "mask;" applied in biological sense 1768 by Linnaeus because immature forms of insects "mask" the adult forms. On the double sense of the Latin word, Carlo Ginzburg, among other students of mythology and folklore, has commented on "the well-nigh universal association between masks and the spirits of the dead."

An animal in an early stage of development that differs greatly in appearance from its adult stage. Larvae are adapted to a different environment and way of life from those of adults and go through a process of metamorphosis in changing to adults. Tadpoles are the larvae of frogs and toads.

The immature, wingless, and usually wormlike feeding form of those insects that undergo three stages of metamorphosis, such as butterflies, moths, and beetles. Insect larvae hatch from eggs, later turn into pupae, and finally turn into adults. Compare imago, nymph, pupa.